Conventionally, in order to connect a rectangular wire electrically to a terminal plate in a terminal plate circuit, it has been carried out by providing a hole, through which the rectangular wire penetrates, in the terminal plate, inserting the rectangular wire through this hole from above or below, and soldering or welding a part at which the terminal plate and the rectangular wire are brought into electrical contact with each other.
However, in a case where the terminal plate circuit is used within a terminal box for solar cell panel, the electrical connection state between the terminal plate and the rectangular wire must be maintained for an extremely long period of time in the severe environment, so that the reliability has not been sufficient by a connection method implemented by only soldering or welding of the aforementioned background art.
On the other hand, as a method for enhancing the reliability of the electrical connection state between the terminal plate and the rectangular wire, it is possible to consider fixing the rectangular wire to the terminal plate with use of a screw and thereafter soldering or welding the fixed part; however, fixation with a screw involves placement of a screw hole and a work of mounting the screw, so that the step will be complex and hence is not desirable.